Impregnating compositions for fibrous sheet materials

ABSTRACT

Impregnating compositions for impregnating flexible sheet materials of a fibrous character, the composition being a mixture of elastomeric material and copolymeric material that imparts pliability and softness to the impregnated fibrous material and in which the copolymeric material is an olefinic copolymer.

United States Patent Muck et a1. 1 1 Aug. 19, 1975 1 1 IMPREGNATING COMPOSITIONS FOR FIBROUS SHEET MATERIALS [56] References Cited [75] Inventors: Eduard Muck, Otrokovice; Jaroslav UNITED STATES PATENTS Strachota, Veseli nad Moravou; 3.100.721 8/1963 Holden 11 7/1355 Josef I-Iorak, Gottwaldov. all of 3.121444 2/1964 Williams 1 17/10 Czechoslovakia 3.190.847 6/1965 Mitchell et al.. 260/29] 3196.016 1/1967 Murphy ll7/1()5.5 1 1 Assigncci Stami y y ustav koledelny, 3.427.192 2/1969 Bolinger 117/139.5 Gottwaldov. Czechoslovakia 3.533.902 10/1970 Hoch 161/170 3.567.499 3/1971 Klebert et a1 117/1395 23] Flled- Sept- 1974 3,639,157 2/1972 Wunder 117 1395 2 Appl- NO: 507 213 3,843,389 10/1974 Enomoto 117/68 Related Application Data Primary liruminerP. E. Willis, Jr. [62] Division of Ser. No. 177.493. Sept. 2. 1971. Pat. No. Attorney, Agent, or Firm-Murray Schaffer [57] ABSTRACT {30] Foreign Applicatlon Prlorlty Data t V I Impregnatmg compos1t1ons for lmpregnatmg flex1ble 1 no C/Mhmhwdkl 6906-70 sheet materials ofa fibrous character. the composition being a mixture of elastomeric material and copoly- [521 5 25 2 meric material that imparts pliability and softness to 2 the impregnated fibrous material and in which the coll7/l39.5 A. 142, 161 UZ. 161 KP. 140 A; 260/29.2TN. 29.2 UA. 29.6 NR

polymeric material is an olefinic copolymer.

3 Claims, N0 Drawings IMPREGNATING COMPOSITIONS FOR FIBROUS SHEET MATERIALS This is a divisional application of Ser. No. 177,493 filed Sept. 2, 1971, now US. Pat. No. 3,852,230.

BACKGROUND OF THE INVENTION This invention relates to impregnating compositions. More particularly it relates to impregnating compositions for impregnating flexible sheet material of a fibrous character and which impart pliability and soft-.

ness to the impregnated fibrous material. Still more particularly, the invention relates to mixtures of elastomeric material and polymeric material suitable for impregnating flexible sheet materials on substrates of tibrous character and in which the polymeric material is formed from lower olefin monomers, that is, those containing 2 to 4 carbon atoms in their chains and substituted olefinic monomers wherein the substituent groups are higher linear alkyl groups, that is, those containing 4 to carbon atoms in their chain or cyclic radicals having the ability to combine with an alkyl radical.

It is generally known to impregnate flexible sheet materials by means of elastomers in the water or organic solvent systems. The flexible sheet materials may be various mats made of natural, animal and vegetable fibres, of a mixture thereof with synthetic fibres, or may be made of synthetic fibres alone, the mats being either woven, knitted or even non-woven. Examples of useful mats are disclosed in US. Pat. application Ser. No. 593,289.

The flexible sheet materials impregnated in the above mentioned manner are comparatively rigid, especially when containing a higher content of the impregnating substances as solids. To remove the undesired rigidity of the flexible sheet materials, it is necessary to choose those conditions of processing which result in a compromise between the impregnating substance content and the rigidity.

In accordance with this invention, a solution to this problem is achieved by use of modified impregnation systems of elastomers either in water or in organic solvent medium. To these elastomeric systems a certain proportion of lowmolecular polymers or copolymers of olefins are admixed so as to desirably influence the pliability of the impregnated flexible sheet materials. As a result, extraordinary values of pliability and softness are achieved with flexible sheet materials.

In accordance with the invention, an impregnating composition comprises a mixture of elastomeric material and copolymeric material, the copolymeric material being formed from (a) olefinic monomers having 2 to 4 carbon atoms in the carbon chain and (b) olefinic monomers having the general formula:

ebulioscopic and cryoscopic methods. Examples of the higher linear alkyls ranging from C to C are butyl-, hexyl-, decylor hexadecyl and the like. Examples of the cyclic systems are cyclohexyl-, phenyl-, alkylphenyland the alphamethylstyrene radical. As employed in this specification and in the claims, a cyclic radical having the ability to combine with an alkyl radical includes radicals derived from aromatic compounds with one or two benzene rings such as styrene and vinylnaphthalene and radicals derived from cycloaliphatic compounds wherein the cyclic portion of the molecule contains 5 to 8 carbon atoms, such as vinylcyclopentane, vinylcyclonexane, vinylcyclohexene and vinylcyclooctane and the like.

A great advantage is obtained by using the lowmolecular weightcopolymers of olefins in organic solvent systems, as a component of these systems, in the form of water dispersions. The water contained in dispersion of these copolymers brings about gelling of the elastomers. The copolymers of the dispersions act at the same time as a protective colloid which results in a stabile micro-gel. When using this micro-gel system for impregnation, excellent micro-capillar structures are achieved in the impregnated flexible sheet materials which substantially increases their sorption and desorption properties.

In the copending application U.S. Ser. No. 177,500 of the same inventors filed even date herewith, now abandoned and assigned to the same assignees coating compositions are disclosed. The disclosure of the aforementioned application is incorporated herein by reference.

Useful organic solutions for the elastomeric material include dimethylformamide and dimethylsulfoxide, tetrahydrofurone and mixtures of these with acetone and benzene and the like. Generally, enough solvent is employed to at least dissolve the elastomeric material. However, as a practical matter, in colutions of elastomeric material in solvent, the solutions may contain about 5 to about 20 percent by weight of elastomeric material based on the total weight of the elastomeric material and solvent.

Generally, the impregnating compositions of this invention are produced simply by mixing the constituents in the desired amounts and room temperature (about 20 C.). However, where necessary, heat can be employed to bring about proper mixing. In this regard, the mixture may be heated to just below its decomposition temperature, if necessary. Usually, temperatures in a range of about 10 C. to about 35 C. are sufficient to provide a homopolymeric mixture. 0

On the other hand, it has been found that best results are secured when using 70% aqueous dispersions of the above mentioned copolymers in water. The dispersion may be added up to the amount of 12%, by weight,

based on the, weight of the elastomers contained in the impregnation system. Moreover, it is to be understood that mixtures of one or more copolymers or elastomers can be employed in the practice of the invention.

An impregnation composition according to the invention may be successfully used in the textile industry,

in the paper making industry, in the garment industry and especially for the manufacture of synthetic leathers as well as in other industries where impregnated flexible sheet materials find their place. I

In order to illustrate the present invention, the following illustrative examples are set forth. In the examples all parts and percents are by weight unless otherwise stated.

EXAMPLE 1 A non-woven textile mat prepared of polyester and viscose fibres was immersed into an impregnation system containing 25% solids. The system comprises 70 parts by weight of a water dispersion of polyurethane, 30 parts by weight of a polyacrylate type elastomer, 40 parts by weight of ammonia solution of a styrene and maleic acid anhydride copolymer, parts by weight of a copolymer of isobutylene with n-dodecene, having mean molecular weight of 1,500, and 3 parts by weight of a water dispersion of ureaformaldehyde resin.

The textile non-woven mat was impregnated with the mentioned system, the excess impregnating material pressed off between two squeegee rollers to leave a deposit of solids in the final product of about 30% of the total impregnated matter. Afterwards, the majority of the water content was removed from the non-woven textile mat by pressing it between two rollers followed by drying at the temperature of 1 15 C. for a period of from 3 to 5 minutes.

The thus prepared mat of non-woven textile material is then buffed and used for further processing. The impregnated material was extremely pliable and soft.

EXAMPLE 2 A non-woven sheet material, made of cellulose, was impregnated by immersion into a bath of total solids content of The bath contained 60 parts by weight of styrenebutadiene-acrylonitrile type elastomer, 25 parts by weight of butadiene-acrylonitrile type elastomer, 2.5 parts by weight of urea-formaldehyde precondensate containing 75% of monomethylol-urea and dimethylol-urea, parts by weight of a polymerization product of isobutylene with alpha-methylstyrene of mean molecular weight 1,000 and 3 parts by weight of an ammonia solution of the ammonium salt of an ethylene and maleic acid copolymer. The bath is a water system. The sheet material was extremely pliable and soft.

EXAMPLE 3 A non-woven mat, prepared of collagen and polypropylene fibres was impregnated by immersing it into an impregnation bath having the total solids content of 17%. The bath contained the following components: 80 parts by weight of polyurethane elastomer Estane 5714 (Trademark of the B. F. Goodrich Company, Akron, Ohio), 15 parts by weight of maleic acid anhydride and styrene copolymers, 5 parts by weight of a copolymer of isobutylene with n-dodecene having an average molecular weight of 1,200 and the appropriate amount of dimethylformamide. After the mat was impregnated the excess impregnation system was removed between two squeegee rollers to leave a solids content in the final product of of the total impregnated matter. Solvent is washed step-wise from the impregnated mat using water, whereby coagulation is effected and micro-structure is formed. When the solvent was washed off the mat was dried for a period of three minutes at the temperature of 1 15 C. It was extremely soft and pliable.

Estane 5714 is a polyether urethane of the type described in U.S. Pat. No. 2,899,411. As such, it comprises the reactive product of hydroxyl poly (tetramethylene oxide), butanediol-1,4, and diphenylmcthane-p,p'-diisocyanate. lt has a Shore Hardness of A, a low tack at elevated temperatures, and a Brookfield viscosity of 6001200 eps.; and it also exhibits excellent low temperature flexibility.

lmpregnation may be obtained by immersion, spray ing, vacuum deposition and other connected means.

EXAMPLE 4 A non-woven textile material made of polyester and polyproplyene fibres was processed in the same manner as described in Example 1 except that instead of 15 parts by weight of copolymer of isobutylene with ndodecene having an average molecular weight of 2,000, 8 parts by weight of copolymer of isobutylene with alpha-styrene having an average molecular weight of 1,500 are used. 1

The elastomeric material and the copolymeric material can be employed in a range of from about parts of elastomers to about 5 to 50 parts copolymers and preferably about 15 to 25 parts of copolymers. More over, in those cases where a minor amount of homopolymerie oil is employed, it is present in a range of from about 5 to 10 parts.

The present invention presents many advantages. For example, the noted compositions of this invention can be made with relatively inexpensive and readily available materials by simple procedures which do not require elaborate equipment and result in greatly improved products. Numberous other advantages will be apparent to those skilled in the art.

It is to be understood that many variations of this in vention may be made without departing from the spirit and scope thereof and that the disclosed embodiments are merely illustrative. Consequently, this invention is not to be limited except as defined in the appended claims.

What is claimed is:

l. A method of impregnating a mat of fibrous material for imparting pliability and softness to the impregnated fibrous material which comprises immersing such a mat into an impregnating composition comprising an aqueous liquid composition consisting essentially of a mixture of about 100 parts of a polyurethane made from hydroxyl poly (tetramethylene oxide), butanediol 1,4 and diphenylmcthane-p,p'-diisocyanate to about 5 to 50 parts of a copolymer having a molecular weight of from about 400 to 3,000 and formed from (a) about l20 molar of an olefinic monomer having 2 to 4 carbon atoms and (b) about 99 to 80 molar of a second olefinic monomer having the formula:

wherein R is a radical selected from the group consisting of linear C alkyl radicals and carbocyclic radicals having the ability to combine with an alkyl radical, said olefinie monomer consisting essentially of hydrocarbon units.

2. A method as defined in claim 1 wherein said aqueous liquid composition contains 70% by weight of solids, based on the total weight of the composition.

3. A method as defined in claim 1 wherein said olefinic monomer of formula I is alpha-methylstyrene. 

1. A METHOD OF IMPREGNATING A MAT OF FIBROUS MATERIAL FOR IMPARTING PLIABILITY AND SOFTNESS TO THE IMPREGNATED FIBROUS MATERIAL WHICH COMPRISES IMMERSING SUCH A MAT INTO AN IMPREGNATING COMPOSITION COMPRISING AN AQUEOUS LIQUID COMPOSITION CONSISTING ESSENTIALLY OF A MIXTURE OF ABOUT 100 PARTS OF A POLYURETHANE MADE FROM HYDROXY POLY (TETRAMETHLENE OXIDE), BUTANEDIOL 1,4 AND DIPHENYLMETHANE-P.P'' DIISOCYANATE TO ABOUT 5 TO 50 PARTS OF A COPOLYMER HAVING A MOLECULAR WEIGHT OF FROM ABOUT 400 TO 3,000 AND FORMED FROM (A) ABOUT 1-20 MOLAR % OS AN OLEFINIC MONOMER HAVING 2 TO 4 CARBON ATOMS AND (B) ABOUT 99 TO 80 MOLAR % OF A SECOND OLEFINIC MONOMER HAVING THE FORMULAR:
 2. A method as defined in claim 1 wherein said aqueous liquid composition contains 70% by weight of solids, based on the total weight of the composition.
 3. A method as defined in claim 1 wherein said olefinic monomer of formula I is alpha-methylstyrene. 